BEIJING (Reuters) - China plans to impose tariff measures of similar size and intensity in its bid to fight back against the United States, as the world's two largest economies engage in a bitter trade dispute.

The comments by the country's commerce ministry came within minutes of U.S. President Donald Trump's announcement that the United States would adopt a 25 percent tariff on $50 billion of goods from China related to intellectual property and technology, and pledged further levies if China took retaliatory steps.

"China is unwilling to have a trade war, but the Chinese side has no choice but to strongly oppose this, due to the United States' myopic behaviour that will harm both parties," the commerce ministry said on its website on Friday.

China's commerce ministry said the measures harm the interests of both countries and disrupt world trade order.

"We will immediately introduce tariff measures of the same scale and strength. All the results from the negotiations previously reached by the two parties will be invalid."

Washington and Beijing appeared increasingly headed toward a trade war after several rounds of negotiations failed to resolve U.S. complaints over Chinese industrial policy, market access and a $375 billion trade gap.

(Reporting by Zhang Min in Beijing and Lee Chyen Yee in Singapore; Editing by Toby Chopra)